What is a likely reaction if a newborn shows edema and a greenish-yellow discharge after eye prophylaxis?

The appropriate response to a newborn displaying edema and greenish-yellow discharge after eye prophylaxis is linked to silver nitrate, which is one of the historical methods used for preventing ophthalmia neonatorum. This eye prophylaxis is typically administered to protect against bacterial conjunctivitis, particularly from Neisseria gonorrhoeae, during the first hours of life.

When silver nitrate is applied, it often leads to a chemical conjunctivitis characterized by the symptoms you mentioned, such as edema and a discharge that can be greenish-yellow. This reaction is usually due to the irritant nature of silver nitrate rather than an actual infection. It is a known effect, where the reaction is common and occurs within the first 24 to 48 hours after application.

In contrast, other medications mentioned like erythromycin, tetracycline, and gentamicin are used for eye prophylaxis as well but tend to have a different side effect profile. Erythromycin and tetracycline are less likely to cause significant edema and the described discharge, and they are generally better tolerated when used in prophylactic settings. Gentamicin, while effective, is primarily used in specific settings rather than as a routine prophylactic treatment for newborns’ eyes against gonococcal infections.